TABLE 1.

Associations between within‐individual and within‐family diagnoses of anorexia nervosa and inflammatory bowel diseases, depending on the order of diagnoses

	Exposure diagnosis	Individuals exposed during follow‐up (N)	Outcome diagnosis	Exposed individuals with outcome diagnosis (N)	HR (95% CI)	p
Within‐individual diagnoses	Prior anorexia nervosa	5042	Inflammatory bowel disease	40	1.44 (1.05, 1.97)	0.024
	Prior anorexia nervosa	5055	Crohn's disease	22	1.60 (1.04, 2.46)	0.033
	Prior anorexia nervosa	5051	Ulcerative colitis	29	1.66 (1.15, 2.39)	0.007
	Prior inflammatory bowel disease	7059	Anorexia nervosa	21	1.30 (0.84, 2.02)	0.241
	Prior Crohn's disease	3521	Anorexia nervosa	9	1.04 (0.52, 2.08)	0.911
	Prior ulcerative colitis	4446	Anorexia nervosa	12	1.26 (0.71, 2.21)	0.468
Within‐family diagnoses	Parental anorexia nervosa	3072	Inflammatory bowel disease	11	0.98 (0.54, 1.77)	0.9813
	Parental anorexia nervosa	3076	Crohn's disease	5	0.87 (0.36, 2.09)	0.756
	Parental anorexia nervosa	3073	Ulcerative colitis	9	1.29 (0.70, 2.59)	0.442
	Parental inflammatory bowel disease	34,874	Anorexia nervosa	123	1.11 (0.93, 1.33)	0.262
	Parental Crohn's disease	13,222	Anorexia nervosa	46	1.11 (0.83, 1.50)	0.486
	Parental ulcerative colitis	25,433	Anorexia nervosa	90	1.12 (0.90, 1.38)	0.304

Note: Hazard ratios (HR) with 95% confidence intervals (CI).